Mary Quarles hugs Rocket as she works with horses at her Ketchen Place Farm in Rock Hill. Quarles and Caitlyn Fletcher share a passion for their horses, a passion shared by many horse enthusiasts in Charlotte and the surrounding areas. "It's huge," says Jerry Simpson, director of the Union County Cooperative Extension. "I believe if you followed a 75-mile radius around Charlotte, through part of Cabarrus, Union, south Mecklenburg and York, you would find more horses than anywhere else." DIEDRA LAIRD - dlaird@charlotteobserver.com